A popular visual effect that can be created using lasers is referred to colloquially as the “Star Wars” effect. This effect describes the sequential activation of lasers so that the beams of light are directed in multiple directions around a room or area creating dramatic effects in the air. This effect has been created by prior art devices by either the use of what is referred to as a beam table or by the use of scanning projectors.
Beam tables are large and bulky devices conventionally use a single powerful laser source inside a large enclosure. The beam tables are heavy and both costly to manufacture and to set up in particular location. In a conventional beam table, the beam is interrupted by rotary or linear actuators or stepper motor actuated mirrors. Each mirror interrupting the beam in sequence redirects the beam upward and out of the enclosure. Then, one or more secondary mirrors, or galvonometer scanner, directs the beam completely out of the assembly to some remote destination. While the device created a pleasing effect, the approach has a number of limitations.
A first problem associated with beam table systems is that they are prone to failure because of the numerous moving parts. Consequently, the devices required frequent service. A single beam table may use four to twelve sets of motor actuated mirrors, as well as multiple optics that have sensitive alignment requirements. Numerous other devices may also be used to achieve beam effects. These systems were expensive to manufacture, complicated to build and had limited control options. In addition, a beam table, a beam table system may have four to five optical surfaces per beam which may require both alignment and cleaning. Because a single laser is responsible for all of the effects, a failure of the laser would prevent the entire system from operating. Likewise, a failure of one of the devices that interrupt the beam may also adversely affect the performance of the entire system.
In addition, in a beam table laser device, the beams originate from a single location. Practically speaking, to substantially fill a room with beams of light, the beams must be reflected one or more times from secondary bounce mirrors located throughout a venue. For example, a beam table that has eight heads, or sometimes called turrets, can shoot eight beams from the device—but each beam would bounce one or more times dramatically extending the reach of the system. Alignments of these components were extremely time consuming, and dangerous, because it forced technicians to be located directly adjacent to the secondary bounce mirror during focusing. Further, the systems were prone to failure. One small shift in a mirror could move a beam many feet by the time the bounce ended. This created both a safety hazard and great setup difficulty.
In contrast with the beam table devices, the system described herein can place a discrete relatively inexpensive laser head in any location up to 200′ from a router device allowing beams to originate anywhere within most indoor venues thereby eliminating the need for secondary bounce mirrors, alignments, and frequent cleaning. Also, beam angles are able to be adjusted easily and safely as the beam can be easily directed to shoot away from the technician and therefore there is not a concern where a particular reflection might end up.
Another problem with the beam table design systems was that these systems involved a single powerful laser beam originating at a diode and ending wherever the final bounce terminated. Each time a laser is reflected, passed through an optic or is interrupted, beam intensity is lost. This effect is further exacerbated by the great distance a beam had to travel through so many bounces because the cross section of the beam gets larger as it travels from its origin, further lowering the intensity of the effect. To compensate for these effects, beam tables traditionally used very high powered lasers which made them more dangerous to work around, more dangerous to focus and increased the hazard to the audience when a reflection went somewhere unexpected.
In contrast, the system of the invention requires zero bounces, can be shot in a straight line any distance and has only two small optics (one inside the laser diode and one external optic) to pass through to create the light beam.
A further disadvantage of beam table systems is that they are difficult to temporarily set up and are therefore not practical for mobile applications. In view of the time that is required to set up the complex system, including time required to place and focus the multiple bounce mirrors and in consideration the of the relative high cost of these systems, there use is for permanent installation such as nightclubs or commercial attractions. Because the costs and fees for the systems in both materials and labor is high, the implementation of these systems and the effect has been limited, notwithstanding the advantages and striking visual effect than can be achieved.
In view of the costs and problems with beam tables and relative acceptable and common use of scanning projectors in connection with laser displays, the scanning projectors have been used to approximate beam table effects or “star wars” laser effects. In an example, a projection scanner can use an electronic modulation of the beam instead of interrupting it with mirrors and then use two scanning mirrors to target the beams to specific X/Y coordinates.
These scanning systems are lighter, more portable, more affordable than beam tables. In addition, they are less prone to failure and have updated features that were not available when the beam was commonly used for the effect. However, scanning projections still have some disadvantage when used for this application.
Like beam tables, a scanning projector still only projects beams from a single source. To get the room filling effect one still would need to use either bounce mirrors or multiple scanning projectors devices. If the installation required bounce mirrors, many of the same problems discussed above are not ameliorated. While, the costs of scanning projectors which have complex control and optical surfaces are relatively high when compared to the laser head disclosed below.
In addition, scanning projectors have limited projection angles when compared to the laser head discussed which can be oriented in any direction on any plane. In this regard, conventional scanning projectors are limited typically to 30-50 degrees on both the X and Y axis from their center point. Scanners are also still prone to motor failure, are fragile since mirrors have to have minimal mass in order to move as quickly as required, and are limited by the resolution of their motors.
Scanning projectors also generally require specialized software to program them to hit certain, specific predetermined points. As such, scanners projectors require additional equipment, additional expense and specialized personnel to program the system. Finally, beams emitted from scanning projectors are often very thin and not nearly as visible as the big thick beams used in the desired effect. The beams from these devices typically have to be quite small due to the relatively small surface area of the galvanometer mirrors. If the beam is too big it spills over the edges of the mirrors causing power loss and ghosting effects. If the beam is compatible with the mirror, it is often less dramatic and visible to the audience.
Building a system using multiple scanning projectors to achieve the effect would be considerably extremely expensive and creates a special safety hazard because if the scanners were to fail when the projector was placed at a desired angle, a relative high powered beam might be accidently directed into an audience area. The prevention of this situation must therefore be addressed which would require significant cost, time and expertise. Even then, a conventional full scanning projectors is large, relatively heavy, expense device and therefore cannot be easily concealed in scenery or an architectural feature.